Why - where else are you going to put them? We currently have both Carrier Strike Group and Littoral Support Group deployed, and are carrying on with normal activities in the Gulf, as part of NATO, maintaining a presence in the Caribbean and the South Atlantic, and maintaining the deterrent. It is quite likely that CSG and LSG would be in the same threatre in a real conflict.
Warships have operated in groups for centuries. How would Nelson have got on if the fleet had been scattered and not concentrated?
I think that it is difficult to argue with the diagram of the aircraft defence zone, the medium range missile zone, and the point defence zone.
Similarly, against a submarine threat you would want multiple helicopters with dipping sonar - which is another carrier role.